The present invention relates in general to molds for casting bullets. More particularly, the present invention relates to bullet molds having a plurality of mold cavities arranged in a plurality of adjacent rows of mold cavities formed between the opposing lateral surface of adjacent mold blocks.
Prior art bullet molds have generally been limited to a single row or bullet casing cavities from between opposing lateral surfaces of a pair of adjacent blocks. In general, the opposing mold blocks are secured to a handle apparatus having a scissor hinge as is shown in U.S. Pat. No. 1,763,977, McNeely and U.S. Pat. No. 3,745,873, Lee.
In devices which do not utilize the scissors hinge, mold blocks are secured to a device having handles at one end and a hinge at a distal end of the device. Exemplary of this manner of joining mold blocks is U.S. Pat. No. 2,380,751, Gowland.
These general approaches to the problem of connecting and operating mold blocks have proven satisfactory so long as the mold itself comprises a single row of mold cavities formed between two adjacent mold blocks. However, due to the requirement of volume production, it is desirable, in certain applications, to provide a plurality of parallel rows of cavities. This approach is desirable in that it allows the fabrication of a mold having a center of mass which is closer to the handles of the mold than a mold having a similar number of cavities arranged in one single extended row, as it reduces the fatique of the operator during the use of the mold.
Prior attempts to produce a hand-operated casting mold having multiple parallel channels of casting cavities have used a hinging device similar to the devices discussed prior. Exemplary of a scissor hinge solution to the problem in U.S. Pat. No. 3,749,351, Lee, which securely fastens an intermediate one of three mold blocks to the pivot pin of the hinge device itself while fastening the outer two blocks to the hinge jaws. This arrangement pivots the external mold blocks entirely out of contact with the intermediate block which is held fixed with respect to the hinge pivot. In thus entirely separating the adjacent mold blocks, the relative alignment between these three mold blocks is controlled solely by the hinge pivot itself until the mold blocks are brought into intimate contact.
A disadvantage of this arrangement is that many manufacturing tolerances or wear between the hinge pivot journals and bearings will allow the mold blocks to move out of registry with each other when the mold is opened. Upon closing the mold, the out of registry blocks are forced into alignment by various devices located between the opposing faces of the adjacent blocks. However, the potential for damaging the opposing faces of adjacent blocks by forcing the blocks into registry when the opposing faces of adjacent blocks are essentially in contact is very great. Once the opposing faces have been damaged, the mold is useless until it is re-conditioned. Any surface irregularities or burrs on a damaged mold block face will prevent an intimate contact between that face and an adjacent mold block face which will result in air space between the mold blocks. This air space will become filled with bullet metal during casting and the resultant bullets which are cast will be useless for their intended purpose to the presence of the fins of bullet metal which have solidified in the air space between the mold blocks adjacent the casting cavities.